57 research outputs found
Nonlinear absorption and nonlinear refraction: Maximizing the merit factors
Both nonlinear absorption and nonlinear refraction are effects that are potentially useful for a plethora of applications in photonics, nanophotonics and biophotonics. Despite substantial attention given to these phenomena by researchers studying the merits of disparate systems such as organic materials, hybrid materials, metal-containing molecules and nanostructures, it is virtually impossible to compare the results obtained on different materials when varying parameters of the light beams and different techniques are employed. We have attempted to address the problem by studying the properties of various systems in a systematic way, within a wide range of wavelengths, and including the regions of onephoton, two-photon and three-photon absorption. The objects of our studies have been typical nonlinear chromophores, such as Ï-conjugated molecules, oligomers and polymers, organometallics and coordination complexes containing transition metals, organometallic dendrimers, small metal-containing clusters, and nanoparticles of various kinds, including semiconductor quantum dots, plasmonic particles and rare-earth doped nanocrystals. We discuss herein procedures to quantify the nonlinear response of all of these systems, by defining and comparing the merit factors relevant for various applications
Influence of Social and Behavioural Characteristics of Users on Their Evaluation of Subjective Loudness and Acoustic Comfort in Shopping Malls
A large-scale subjective survey was conducted in six shopping malls in Harbin City, China, to determine the influence of social and behavioural characteristics of users on their evaluation of subjective loudness and acoustic comfort. The analysis of social characteristics shows that evaluation of subjective loudness is influenced by income and occupation, with correlation coefficients or contingency coefficients of 0.10 to 0.40 (p<0.05 or p<0.01). Meanwhile, evaluation of acoustic comfort evaluation is influenced by income, education level, and occupation, with correlation coefficients or contingency coefficients of 0.10 to 0.60 (p<0.05 or p<0.01). The effect of gender and age on evaluation of subjective loudness and acoustic comfort is statistically insignificant. The effects of occupation are mainly caused by the differences in income and education level, in which the effects of income are greater than that of education level. In terms of behavioural characteristics, evaluation of subjective loudness is influenced by the reason for visit, frequency of visit, and length of stay, with correlation coefficients or contingency coefficients of 0.10 to 0.40 (p<0.05 or p<0.01). Evaluation of acoustic comfort is influenced by the reason for visit to the site, the frequency of visit, length of stay, and also season of visit, with correlation coefficients of 0.10 to 0.30 (p<0.05 or p<0.01). In particular, users who are waiting for someone show lower evaluation of acoustic comfort, whereas users who go to shopping malls more than once a month show higher evaluation of acoustic comfort. On the contrary, the influence of the period of visit and the accompanying persons are found insignificant
Fingerprints of Through-Bond and Through-Space Exciton and Charge Ï-Electron Delocalization in Linearly Extended [2.2]Paracyclophanes
New stilbenoid and
thiophenic compounds terminally functionalized
with donorâdonor, acceptorâacceptor, or donorâacceptor
moieties and possessing a central [2.2]Âparacyclophane unit have been
prepared, and their properties interpreted in terms of through-bond
and through space Ï-electron delocalization (i.e., Ï-conjugations).
Based on photophysical data, their excited-state properties have been
described with a focus on the participation of the central [2.2]Âparacyclophane
in competition with through-bond conjugation in the side arms. To
this end, two-photon and one-photon absorption and emission spectroscopy,
as a function of temperature, solvent polarity, and pressure in the
solid state have been recorded. Furthermore, charge delocalization
through the [2.2]Âparacyclophane in the neutral state and in the oxidized
species (radical cations, dications and radical trications) has been
investigated, allowing the elucidation of the vibrational Raman fingerprint
of through-space charge delocalization. Thus, a complementary approach
to both âintermolecularâ excitation and charge delocalizations
in [2.2]Âparacyclophane molecules is shown which can serve as models
of charge and exciton migration in organic semiconductors
FUT2 Variants Confer Susceptibility to Familial Otitis Media
Non-secretor status due to homozygosity for the common FUT2 variant c.461G>A (p.Trp154â) is associated with either risk for autoimmune diseases or protection against viral diarrhea and HIV. We determined the role of FUT2 in otitis media susceptibility by obtaining DNA samples from 609 multi-ethnic families and simplex case subjects with otitis media. Exome and Sanger sequencing, linkage analysis, and Fisher exact and transmission disequilibrium tests (TDT) were performed. The common FUT2 c.604C>T (p.Arg202â) variant co-segregates with otitis media in a Filipino pedigree (LOD = 4.0). Additionally, a rare variant, c.412C>T (p.Arg138Cys), is associated with recurrent/chronic otitis media in European-American children (p = 1.2 Ă 10â5) and US trios (TDT p = 0.01). The c.461G>A (p.Trp154â) variant was also over-transmitted in US trios (TDT p = 0.01) and was associated with shifts in middle ear microbiota composition (PERMANOVA p 20 were combined, FUT2 variants were over-transmitted in trios (TDT p = 0.001). Fut2 is transiently upregulated in mouse middle ear after inoculation with non-typeable Haemophilus influenzae. Four FUT2 variantsânamely p.Ala104Val, p.Arg138Cys, p.Trp154â, and p.Arg202ââreduced A antigen in mutant-transfected COS-7 cells, while the nonsense variants also reduced FUT2 protein levels. Common and rare FUT2 variants confer susceptibility to otitis media, likely by modifying the middle ear microbiome through regulation of A antigen levels in epithelial cells. Our families demonstrate marked intra-familial genetic heterogeneity, suggesting that multiple combinations of common and rare variants plus environmental factors influence the individual otitis media phenotype as a complex trait
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